Rotary internal-combustion engine



June 19,1928; 1,674,449

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ROTARY INTERNAL COMBUSTION ENGINE Filed Now 24, 1925 2 Sheets-Sheet 1June 19, 1928. 1,674,449

, A. M. RIGGS ROTARY INTERNAL COMBUSTION ENGINE Filed Nov. 24, 1925 2Sheets-Sheet 2 Patented June 19, 1928.

' AsntnY 11:. areas, or HARRISBURG, PENNSYLVANIA.

ROTARY INTERNAL-COMBUSTION ENGINE.

Application filed November 24, 1925. Serial No. 71,075.

' shaft and its bearings and to effect reduction of vibration.

A still further object is to structurally improve, simplify and rendermore practical the structure disclosed in-United States Letters PatentNo. 1,225,056, granted jointly to Lewis \V. Riggs and myself on the 8thday of May, 1917.

In describing the invention in detail, reference is herein had to theaccompanying drawings, in which Figure 1 is a transverse sectionalelevation of the invention, the section being taken substantially online 11, Fig. 2;

Figure 2 is a longitudinal section taken substantially on line 22, Fig.1;

Figure 3 is an outer face view of a cornpression head;

Figure 4 is a cross section on line-4-4, Fig. 3;

Figure 5 is a lateral edge View of the compression head; a

Figure 6 is a partial detailed section of a fragmentary portioniof therotor;

' Figure 7 is a section on line 7-7. Fig. 6;

Figure 8 is an inner face elevation of a fragmentary portion of one ofthe pistoncarried rings, showing the sealing blade:

Figure 9 is a section on line 9-9, Fig. 8; and

Figure 10 is a detail section showing the relative positions of theparts at, or slightly in advance of, the firing point.

Referring to said drawings, 1 indicates the outer wall of a hollowcasing or cylinder 50 which has heads 2 and 3 rigidly mounted upon itsopposite ends, said heads having formed therein suitable centrallylocated bearings in which is journaled a rotor shaft 4. Keyed upon saidshaft within said cylinder 1 is the hub portion 5 of a rotary piston,

or rotor, which comprises an outer body portion (5, substantiallycircular in form, and two circular facing rings 7 and 8"which arerigidly attached to opposite sides of said form cam surfaces, the,urpose of which will be explained hereina ter; and the ring 8 has 1tsouter face forming a close joint with said cam.

The piston body 6, which is preferably formed in one piece,-has thereina plurality of external pockets 11 of substantially triangular formarranged at equi-distant intervals, four such pockets being embodied inthe structure herein illustrated; and fitted for oscillating movementsin each pocket is a compression head 12 which comprises a wall 12'having its outer face curved to adapt it for seating closely against thecylinder wall 1 when occupying its extreme outward position, and aforward end wall 12 which i extends inwardly in a substantially radialdirection and which is movable in closely seated joint-forming relationto the front wall 13 of said pocket. Said wall 12 is made of materiallyless length, radially considered, than the depth of the front end of thepocket, so that the compression head'is allowed a considerable range ofoscillatory movement in said pocket. A bolt or pivotpin 15 is carried bythe piston body adjacent to the rear end of each pocket 11, the hole 16within which said pivot-pin is seated being in open communicationthroughout its length with the pocket, thus presenting within said endof the pocket somewhat less than one-half the peripheral surface of thepivot-pin. The rear end of the wall 12 of the compression head hastherein a shallow undercut channel or groove 17 having a curvaturecorresponding to the peripheral curvature of the pivot-pin; Thus, in theoscillating movement of "the compression head, the rear end of thelatter rides upon and is supported by said pivot-pin.

The front end wall 13 of the pocket 11 is curved, the curve being struckorrthe radius of a circle having as its center the pivot-pin 15, and thefront wall 12 of the compression head is correspondingly curved, so thata close fitting relation is at all times maintained between said. walls.

, follow the tortuous path provided by." the v Each compression head isformed of two y extending sections disposed inner edge of one sectionhaving therein a groove 18 within which is received a tongue 19' formedon the adjacent edge of the other section; and disposed in sockets 20provided therefor at the bottom of said groove are compression springs22 which yieldingly bear against the rib for maintainlng said sectionsin relatively separated or expanded position so that their outer lateraledges bear against and ride upon .the adjacent faces of the rings 7 and8 and the faces of ring segments 23 which are carried by said I rings.'Said segments are mounted in recesses 24 provlded' therefor 1n theinner faces of said rings at points located laterally of the pockets andhave their inner edges resting upon small compression springs 25 whichact to maintain them yieldingly thrust outward with their outer edges inclose sealing relation to the cylinder walll.

Carried by the forward end wall 12 of the compression head is alaterally directed pin26 which extends outward through a substantiallyradial slot 27 provided therefor in the ring-8. The outer end portion'of said pin rides upon theperipheral surface of the cam ring 10. 'Aretractile coil spring 28 is interposed between the under side of theforward end portion of the compression head 12 and the piston body at asuitable point within the pocket .11. Thus, said compression headisnormally held under yielding tension in an inwar y drawn position inwhich the pin'261is -maintained permanently in seated relation to thecam ring 10, causing the pin co'nfo-rmably to peripheral surface of saidring.

Provided in the cylinder 'wall 1 at diametrically opposite points areports 29 through which are admitted charges of the explosive gases-ormixtures employed; and

mounted in said wall at diametrically oppo-- site points located atanglesof approximately ninety degrees with respect to said,

intake ports 29 are spark plugs 30 through which the admitted chargesare fired electrically for-driving the piston.

As each compression head approaches one of the intake ports 29, theguide pin 26 carried thereby rides upon an elevated surface 10 of thecam ring, holding the compression head in close engagement with thecylinder wall 1. Immediately prior to reaching such port, said pin ridesdown an abrupt incline 10 to a relatively lower surface 10 of said camring in which the compression head, actuated by its spring 28, is

lowered to its greatest extent with respect to said cylinder wall. Inthe lowering movel ment a. suction is created which,'in the interval ofpassing said port, results in filling with the explosive mixture theportion of the pocket exterior to said compression head. Having passedsuch intake port, the com pression head is gradually elevated, the guidepin riding up an inclined surface 10 of the cam ring for effecting suchelevation of the compression head. In suchelevating movement, theadmitted charge is compressed into'an auxiliary pocket 31 of relativelsmall capacity which is located in fron of and in ofi'set relation tothe front endof the pocket 11, as shown in Figs. 1 and 10. As the pistonassumes a posltion in which said auxiliary pocket 31 is disposed in opencommunication with the opening or socket 32 in which the spark plug 30is mounted, the uide pin 26 starts to move inwardover a s arply inclinedsurface 10 of the cam ring. Atthis point in the operation, or with theparts occupying substantially the positions shown in Fig. 10, thefacingwall which receives the impact of the explosion- In said position, theresistance head has the frontend portion thereof firmly seated upon theouter surface of the compression head 12,being actuated to said positionby a compression spring 35 which has suitable connection, as through alink 36, with said resistance head. Rigidly mounted 'upon the-exteriorof the cylinder wall 1 in closing relationto the aperture 34 is aplate-like member 37 having a socketed portion 38 within which saidspring 35 is seated, as shown.

The resistance head 33 comprises a platelike body portion which ismovable into and out of the aperture 34 and which is pivoted at its rearend upon a'transverse bolt or pivot pin 39. Formed integral with thefront end portion of said body is an outwardly extending blade portion33 which is exposed to the impact of the explosions and which serves toresist the rearwardly directed force of the latter. With movements ofthe resistance head said blade portion 33 moves into and-out of aguide-' sistance head 33 is held in its outwardlythrust position exceptin the intervals in which compression heads 12 passing thereunder occupylowered positions, in which intervals it isv actuated by its spring 35to follow the lowering movements of the compression heads. As isobvious, return, or outward, movement of said resistance head isgradually effected as the depressed compression head advances fromthereunder.

Following the explosion of the compressed gases, the wrist pin 26continues to the foot of the inclined surface 10", whence it immediatelybegins ascent of a gradually inclined cam surface 10 for effectingclevation of the compression head 12 against the cylinder wall 1,thereby gradually to force the spent gases outward through an exhaustport 45 provided at an appropriate point in the cylinder wall in advanceof the position of the spark plug 30.-

Suitable means are provided for preventing leakage of gases rearward ofthe compression heads 12, as transversely disposed radially movablescavenging blades 41 seated in channels42 of the piston upon smallcompression springs 4-3. Similar means, as spring pressed blades 44, arelocated directly in front of each auxiliary pocket 31, as shown.

It will be noted that, as shown in the drawings, four compression headsare employed on the piston, and that each head is actuated twice in eachrotation of the rotor to admit and compress charges of gas which arefired at diametrically opposite sides of the cylinder. Consequently,eight power impulses are delivered, two at a time, in each rotation ofthe rotor.

What is claimed is I 1. A rotary explosion engine comprising a cylinderhaving heads mounted upon opposite ends thereof, a cam ring'carried byone of said cylinder heads, a substantially cylindrical piston rotatablewithin said cylinder, rings rigidly carried on opposite ends of saidpiston and having their peripheries engaging the cylinder walls, saidpiston havinga plurality of pockets in its'periphery between the lastmentioned rings, said rings having therein recesses located laterally ofsaid pockets, spring pressed ring segments 1n said recesses, acompression head pivotally mounted within each of said pockets andmovable to and from seating relationto the cylinder walls, a laterallyextending wristpin carried by each compression head, resilient meansholding each compression head in a position wherein its wrist-pin ridesupon said cam ring, the adjacent pistoncarried ring having substantiallyradial slots through which said wrist-pins are directed and in whichsaid pins are movable, and resistance heads carried by the cylinder forcooperating with said compression head.

2. A rotary explosion engine comprising a cylinder having heads mountedupon oppositeends thereof, a'cam ring carried by from seating relationto the cylinder walls,

a laterally extending wrist-pin carried by eachcompression head, saidcam ring being shaped peripherally to actuate said compression headsthrough said wrist-pins to move outward at timed intervals, the adjacentpiston carried ring having therein slots in which said wrist-pins havemovement, tension means tending to maintain each compression head ininwardly drawn position, and resistance heads carried by the cylinderand movable into said pockets for cooperating with said compressionheads.

3. A rotary explosion engine comprising a cylindrical casing havinginlet and exhaust ports therethrough and provided with diametricallyopposite apertures, a member mounted on said casing in closing relationto each of said apertures, a pivoted resistance head in each of saidapertures and movable into and out of the interior of said casing, apiston rotatable within said cyl inder and having a lurality of pocketsformed in its perip ery, spring-pressed radially movable seating memberscarried by said piston at opposite sides of said pockets, a compressionhead pivotally mounted in each of said pockets and movable into and outof seated relation to the walls of said casing, a cam ring fixedinteriorly of one end of the cylinder, wrist-pins carried by saidcompression heads, resilient means constantly maintaining saidcompression heads in positions wherein their wrist-pins follow thecontour of the periphery of said ring, and resilient means foractuatingsaid resistance heads to follow the movements of said compression headsas the latter pass under the former.

In testimony whereof, I afiix my signature.

ASHLEY M. RIGGS.

